Abstract: A magnetoresistive device includes an MR element including a metal layer, and an insulating portion made of magnesium oxide and in contact with the MR element. A method of manufacturing the magnetoresistive device includes the step of removing an unwanted magnesium oxide film that is formed by the magnesium oxide in the process of forming the insulating portion. In this step, the unwanted magnesium oxide film is wet etched by using an etchant containing an aqueous ammonia solution.

Abstract: A magnetoresistive device includes an MR element including a metal layer, and an insulating portion made of magnesium oxide and in contact with the MR element. A method of manufacturing the magnetoresistive device includes the step of removing an unwanted magnesium oxide film that is formed by the magnesium oxide in the process of forming the insulating portion. In this step, the unwanted magnesium oxide film is wet etched by using an etchant containing an aqueous ammonia solution.

Abstract: A method of manufacturing a magnetic head apparatus provided with a slider having an ABS includes a step of aging a bar with a plurality of sliders, a step of lapping a surface or the bar, the surface including the ABS to be formed, the lapping step including a final lapping process for finally lapping the surface of the bar, a step of forming rails of the respective sliders of the bar after the final lapping process, the forming step including a photolithographic etching process to form the rails, and a step of cutting the bar to separate into the individual sliders. The aging step is carried out before the final lapping process or with the final lapping process.

Abstract: A head piece aggregate which includes a plurality of columns of thin-film magnetic head elements is cut from a wafer which is provided with a plurality of thin-film magnetic head elements arrayed in a lattice-like pattern on a base body. The thin-film magnetic head elements in the columns included in the head piece aggregate thus cut out have the same directionality on a given surface. Then, one of the two cut surfaces of the head piece aggregate is attached to a mounting tool so that polishing can be performed on the other surface. Next, the uppermost column of the plurality of columns included in the head piece aggregate is cut away from the others. Deviation in throat height caused by bow and bend of the head piece aggregate can, thereby, be prevented.